Polycrystalline superabrasive materials like polycrystalline diamond (PCD) and polycrystalline boron nitride (PCBN) are commonly demanded with high wear resistance, high toughness, and high thermal resistance as they are applied in abrading of material which is difficult to machine, drill, or cut. Conventional polycrystalline superabrasive tools tend to satisfy one property at the sacrifice of another. For example, higher wear resistance typically results in lower toughness. Each property does not correlate with one another with respect to their behavior and property values in the materials that are a key ingredient in ultrahard, superabrasive tools. Thus, the industry continues to seek tools which satisfy all of the above properties.
In order to achieve certain properties in polycrystalline diamond composite tools, the polycrystalline diamond layer has typically been increased in thickness. An increase in thickness generally results in an increase in technical difficulties associated with making quality polycrystalline diamond composites. For example, infiltration of sintering aid through a thicker layer tends to be limited such that sintered diamond quality tends to decrease with increased layer thicknesses. As technical difficulties associated with making quality polycrystalline diamond composite tools increase, the resulting thermomechanical properties in the polycrystalline diamond composite tools have diminished reliability. As such, composite tools having increased thermal resistance, toughness and wear resistance, and methods of forming the same continue to be sought through ongoing research and development efforts.